


Yours is the Only Ocean

by seapigeon



Category: Captain America (Movies)
Genre: Alternate Universe, Cryptids, Families of Choice, Interspecies Relationship(s), Interspecies Sex, M/M, Siren!Steve, mer!Bucky
Language: English
Status: Completed
Published: 2019-12-12
Updated: 2019-12-12
Packaged: 2021-02-25 21:48:31
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 6,256
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21762496
Author URL: https://archiveofourown.org/users/seapigeon/pseuds/seapigeon
Summary: "Sirens aren’t monogamous.  She’s free to mate with whoever she wants.” Steve turns his head, and for the first time, he looks tentative.  “So am I.”It takes Bucky almost a full minute to understand.“Oh,” he says, going warm down to his tailfin.
Relationships: James "Bucky" Barnes/Steve Rogers
Comments: 52
Kudos: 609





	Yours is the Only Ocean

**Author's Note:**

  * For [Deisderium](https://archiveofourown.org/users/Deisderium/gifts).



> So, I wanted to write something to mark a small but happy milestone: 100 followers on Twitter. I asked for prompts and the lovely Deisderium suggested cross cryptid romance, friends to lovers. I've never ventured far into the land of cryptids, so this was a delicious and fun challenge!
> 
> I really hope you all like it, and if you want to follow me on Twitter, I'm @seapigeon1.
> 
> Thank you all for your ongoing support!

“What a freak.”

Bucky looks up, curious. The others have their heads poked above the surface. He’s been staying below because, one, he prefers to after the harpoon to the left shoulder and subsequent bout of captivity a few years back, and two, he can hear an awful screeching through the vibrations in the water. Why would he want to go up and hear _that_ more clearly?

“What is it?” he asks. They can’t hear him, though. The air up above doesn’t conduct sound the same way as water. If he wants to know, he has no choice but to surface.

He takes a breath and flicks his muscular tail. The air above is cold but bracing. It feels strange in his mouth and nose; it’s been a while since he breathed this way. 

There’s a man on an outcropping a little ways off, and that’s where the racket is coming from. He’s singing. Although that can barely be considering singing; it’s painfully bad. Why is he perched there warbling his inelegant tune?

Ah. He’s not a man. He’s a...siren? Bucky blinks, confused. Most of them are female, although he has heard that there are male sirens, too. He’s never seen one before, in all his trips around the oceans of the world. He can’t help but stare.

The siren is slight of frame, with a large nose and ears that stick out. His hair is sandy blond and flops into his eyes. He has fine bones and ribs that Bucky can count. He frowns to himself.

“He’s not much to look at,” Tony snorts. 

“Neither are you,” Rhodey deadpans in return. Rhodey is joking, but Bucky is glad he didn’t have to be the one to say it. He likes Tony, but sometimes he has a mean streak. He’s one to talk, anyway. He’s scarred just like Bucky, on his chest courtesy of a boat propeller. He’s always been far too interested in human technology. It was inevitable that one day he’d get too close and pay the price.

Tony isn’t cowed, though. 

“It’s a miracle he hasn’t starved. He sounds like a dying whale.”

“Dying whales sound better,” Maria comments.

Bucky just continues to frown. What if he _is_ starving because he can’t sing? It bothers him more than it should. His kind avoid the sirens, but nobody harbors any illusions about what they do with the people they catch. Every creature has its place in the food chain. Unless, of course, they can’t hunt properly.

“Bucky,” Clint says, surprised. “When did you come up?” 

“Just now,” he murmurs, thoroughly distracted. He can’t stop thinking about this poor siren that seems to have been screwed by the genetic lottery.

“You haven’t been above water in three years,” Bruce points out.

“Uh huh.”

“This guy is so bad that even _Bucky_ had to come up to get his ears assaulted,” Tony snickers.

“Leave him alone,” Bucky returns, unsure why he feels so defensive. “It’s not his fault.”

“No,” Pepper agrees. She’s wearing a sympathetic expression; she’s the kindest and most compassionate of them all. “It’s not. And he’s doing his best.”

Clint considers it and nods. “You know, I bet he attracts prey just fine, because they come to see what the racket is. It works for him and that’s what matters.” If Pepper is the kindest, Clint is a close second, and easily the most accepting of oddity. He brought Bucky into the fold, after all.

And yeah, Clint has a point, but what if it _doesn’t_ work for him? Usually a siren’s singing stupefies its prey, so they don’t fight their fate. But even if he lured someone close enough, his song isn’t exactly hypnotic, and he doesn’t look strong enough to take down a fully grown human with all their wits about them.

Bucky chews his lip. He’s so _thin_.

It’s not his business, though. Sirens have been known to eat merfolk when they’re hungry enough, and they definitely aren’t social creatures. This one won’t want his company or his concern. So what if Bucky was hungry once, held captive by humans who didn’t know what to feed him. So what.

He ducks back under the water and swims away, and after a minute, the pod follows. 

  
  


Sam shows up after sunset and tosses a fish at him. Steve bares his teeth.

“Sam, how many times do I have to tell you _I can get by on my own?_ ”

“Just eat the damn fish,” Sam replies, heaving his lithe body up onto the rocks. Sam is everything Steve is not; he’s muscular, gorgeous, and has a voice to (literally) die for. “Come on,” he says in a gentler tone. “It’s been five days. I know you’re hungry.”

“We’re all hungry this time of year.”

It’s true. There are fewer people out on the water in the colder months. Those who do come out are fishermen who know better than to follow a sweet voice. In these times they survive on fish, and Steve is more than proficient at catching them when the water is warm and they stay close to shore, but now they’ve either left altogether for warmer waters, or retreated further out to the shelter of a temperate current. His lungs don’t let him swim that far.

It never stops him from trying, though. It’s not like he’ll _drown_. He has gills, but they work about as well as his terrestrial lungs. Last winter, it took him days to get back, with absolutely nothing to show for it. Sam had been coming once or twice a week since then.

That was how they met, actually. Sam saw the vacant outcropping, perched nicely over an invisible shoal that has ruined the hulls of many boats. He saw the same potential that Steve’s mother had, once upon a time.

Sirens can be territorial, not to mention _really fucking rude_. More than once Steve has had to defend his spot. It always ends with him battered and bloody, but every time, he just keeps getting up, refusing to yield. So far they’ve all eventually decided it wasn’t worth the trouble of actually killing him.

He thought he would have to fight Sam, too. But Sam took one look at him after six days at sea, wheezing and shivering, and moved right off his rock. It’s a testament to Sam’s magnanimity that he actually offered a piece of his meal to Steve that day, and then didn’t balk when Steve archly informed him that he didn’t eat human, thank you very much.

Not _all_ sirens are rude and antisocial.

Steve sighs and reaches for the fish. It’s his favorite. Sam’s thoughtful like that.

  
  
  


An hour later, Natasha crawls up from the sea. Humans would call her his neighbor _._ On clear nights, he can hear her song drifting on the wind. 

She is the pinnacle of their species, Steve thinks. Beautiful, cunning, and absolutely lethal. He can’t remember exactly when she arrived. Just that she swam by looking to mate instead of fight, and somehow didn’t immediately change her mind when she saw (and _heard_ ) him. 

They have, a few times, but there haven’t been any pups. Perhaps that’s for the best. 

The three of them are quiet for a long while. There’s a lot of silence. Silence is treasured among his people; it means rest. Comfort. A chatty siren is not one that’s likely to have many companions.

Others mistakenly think that means they prefer isolation, but most sirens exist in small groups of three to six that live close together. Natasha and Sam are his kin. He’d do anything to protect them. Especially after having to wait so long to find them.

Silence is treasured, but there was far too much of it after his parents died. For a long time, he thought he’d be alone forever. Who would want someone so flawed as kin?

“There was a pod of merfolk out there earlier,” he says after another hour, watching the moonlight play over the fish scales flaked over the rocks.

“Oh?” Natasha perks up. “I like merflesh.”

“They were laughing at me.”

Her eyes narrow, and Sam sighs.

  
  


He can’t stop thinking about him - the hungry siren.

Two days later, he swims back toward the island. He doesn’t tell anybody he’s going. That’s two milestones in one week; he hadn’t been above water in three years, as Bruce so astutely shared, nor had he traveled anywhere alone in about the same amount of time. 

Sure enough, he’s still there. He’s in the water this time. His movement is graceful enough, but Bucky can hear his noisy breathing. There’s something wrong with his lungs. He’s willing to bet that’s why he can’t sing.

The siren pulls himself back up onto his outcropping. It’s warmer today and the sun is shining. The water dries on his skin as Bucky watches. 

Tony was wrong. Bucky thinks he’s beautiful, in his own way. He just wishes there was a little more meat on his bones.

“Come back to laugh some more?” the siren calls out, and Bucky is shocked. His singing voice is rubbish, but his speaking voice is deep and smooth.

“I wasn’t laughing at you.”

He flicks a fishbone off the rocks. “Your friends were.”

“Some of them.”

“What’s the point of having cruel friends?”

“They’re not. They’re just stupid sometimes.”

The siren considers it, and after a while, he seems to accept that. Maybe he has some stupid friends, too. 

“Why did you come back, then?” 

Bucky’s tail twitches. “To see if you were hungry.”

He grins, and Bucky can see his rows of tiny, razor-sharp teeth.

“Gonna offer me a bite?”

“N-No. A fish, maybe.” He _hates_ that little stutter, but it creeps up on him when he’s nervous ever since those long months in the too-small enclosure. So do the nightmare images of human faces pressed up against the glass, gawking in ignorant wonder.

The siren rolls his eyes. “Now even the merpeople are trying to feed me.” He crosses his arms over his chest, the picture of proud obstinacy. “I don’t need your help!”

“Okay.” Bucky looks down at the water. “Sorry to bother you.” He follows his glance and goes under, gliding away. It was dumb and now it’s done.

  
  
  


Except it’s not, because a week later he’s out gathering the pod’s favorite seaweed when he sees the siren. At first he thinks he must have hit his head or eaten a piece of seaweed with that psychotropic algae growing on it, because why the hell would the siren be all the way out here? He’s leagues offshore. But it’s him, and he’s struggling.

His breathing sounds worse than it did the other day. Without thinking, Bucky swims toward him. It’s immediately apparent why he sounds so terrible; there’s a sizable fish in his mouth and he’s trying to draw air around it.

“Hey!” Bucky calls. 

“I’m _fine_ ,” is the first thing he says, comically muffled around the fish. He’s not fine. Bucky thinks he gets it, though. He’s probably been treated like he’s inferior his entire life, and because of that, he won’t admit to needing help. He refuses to prove people right. It makes Bucky like him immensely, even if it is kind of idiotic.

“I know, I know,” Bucky agrees. “I just wanted to offer to carry that back in my basket, so we can talk.”

“I prefer silence.”

Bucky controls a smile. “That’s fine, too.”

“You sure you don’t just want an easy meal?” the siren asks, sarcasm and skepticism practically married in his voice.

“Something tells me that if I tried to take that from you, it would be anything but easy.”

He sniffs, but he relaxes his guard a little. He takes a moment to think about it, and in that moment Bucky indulges his curiosity. This is the closest he’s ever been to a siren. His skin is subtly scaled, flesh-colored but iridescent in the sun. There are gills at his neck and webbing between his fingers and toes. He’s built for swimming, but not in the same way as Bucky.

“Okay,” he says at last. He holds the fish out to Bucky, looking like he fully expects him to swim away laughing. Had people been so unkind to him in the past? His demeanor says yes.

“Hold on here,” Bucky offers, indicating the strap where the basket goes over his shoulder. “That way you know I can’t make off with your dinner.” _And I can tow you along so you don’t have to work so hard._

He isn’t fooled, but he doesn’t protest, either. Bucky flicks his tail and they’re off.

  
  
  


He waits a while before he talks, trying to be respectful. They have a nice rhythm going, Bucky’s tail and his webbed feet propelling them along at a good clip. It’s strangely relaxing.

“What’s your name?” he asks.

His answer is grudging. “...Steve.”

“I’m Bucky.”

“You shouldn’t hang around my kind. Some sirens like to eat merfolk.”

“You don’t?”

“No. I don’t like to eat anything that might have a family.”

Huh. That is definitely not on brand for a siren; as far as Bucky knows, they’re gleefully carnivorous and undiscriminating.

“Sometimes I even feel bad about the fish. When I was younger, I tried just eating plants and invertebrates, but it wasn’t enough. I got pretty sick.” 

“It’s better with the fish?”

Steve nods. “I mostly eat the invasive ones. You know, the ones the humans drop in places they don’t belong and then get mad that they do what they exist to do.”

Bucky knows much more about humans than he ever wanted. It makes him go quiet for a minute. He reaches for a change of subject; if he dwells, it takes him to a dark place.

“I could ask one of my podmates to make you a basket. That way you can bring back more than one fish and not have to hunt as much.”

Steve makes direct eye contact for the first time. His eyes are very blue.

“You’d do that?”

“Sure.” He aches a little, because it’s so obvious that Steve has been shown far too little simple kindness in his life.

Steve doesn’t answer right away. They’re in view of his outcropping by the time he finally does.

“Okay,” he says, low and solemn. “What do you want for it?”

“Nothing.”

Steve gives him a look. Oh. It can’t be an act of charity or just a nice favor; his pride won’t stand for it. Bucky asks for the most benign thing he can think of.

“I want you to be my friend.”

“You have strange taste in friends.”

That is probably true. Bucky smiles and extracts Steve’s lionfish from the basket.

“See you soon.”

  
  


He’s sitting in companionable silence with Natasha when he sees the blue tail break the surface. Natasha is instantly awake even though she was in something of a post-meal haze just a minute before. She really _does_ like merflesh.

Steve reaches out to catch her arm. She looks at him, eyebrow raised.

“Not that one. That one’s my friend.”

“Your friend,” she repeats.

“You got water in your ears?”

She ignores his cheek. “Is this one of the merpeople that was laughing at you?”

“No.”

Natasha looks out at the merman. Bucky is keeping his distance; he’s smart enough not to assume that just because Steve is friendly, his company is, too. Wise, when it comes to Natasha.

“Well,” she says, in a tone of mild disappointment, “if you vouch for him, I guess I won’t eat him.”

  
  
  


Steve’s other friend - Natasha, is it? - is terrifying. Not just because he can tell that she is a much more typical (and successful) siren. The whole time he’s interacting with Steve, he can feel her eyes on him. She is most definitely judging his worthiness, and it’s pretty clear that if he does anything to hurt Steve, she will make him pay.

He’s glad that Steve has someone who cares. He just wishes she was slightly less intimidating.

“Don’t worry about her,” Steve says with a fond look, once she’s departed. “She’s kin.”

He doesn’t know exactly what that means to sirens, but it’s the softest Steve has looked. Bucky wants that look and that tone of voice for himself. The feeling comes on quick and surprises him. He hasn’t wanted much except safety and the sea in a while.

“I’ll take your word for it.”

“Your pod - are they your kin?”

“We’re not related, but they are my family.” 

They took him in without question and cared for him when he was too numb and befuddled to do it himself. Captivity made him stupid and slow and fearful. It can’t have been an easy job, early on. Bruce said it was malnutrition combined with psychosis; Bucky is inclined to believe him. He still doesn’t know how he managed to get it together long enough to escape. He suspects he had help that he can’t remember.

Steve nods to himself, as if he’s satisfied with the answer.

  
  
  


“Hooray for independence and all that,” Tony starts, a few months later, “but where are you actually going?”

It’s been killing him not to ask. Respecting boundaries is not Tony’s strong suit, and Bruce and Rhodey’s admonishments only go so far.

“Remember that siren?” Bucky asks.

“Siren?” is the mystified response. Tony blinks a few times and then his eyes light up. “You mean the one that sounded like an orca in heat but _so much worse_?” 

By now Bucky knows singing is a biological imperative for sirens. Steve is fully aware of how terrible his voice is, but he has to sing at least once a day or else he’ll go a little crazy. Sort of like how Bucky needs the ocean, or he’ll lose his mind. He knows that one firsthand.

“Yeah, that’s him,” he says through his teeth. He was insulted on Steve’s behalf before he even knew him, and now it’s worse.

“What about him?”

“We’re friends. I’ve been spending time with him. Hunting together, sometimes. For _fish_ ,” he clarifies, at Tony’s horrified glance. That doesn’t go far to mollify him. 

“That basket you asked Pietro to make--”

“It was for him.”

“Bucky.” Tony’s hands are on his shoulders and he gives him a little shake. “Bucky, one of the reasons you got caught was because you’re -- you’re too friendly. Too curious. You said it yourself. I know you’re feeling better lately but that doesn’t mean you can just...”

He watches Tony struggle for words. He knows the concern comes from a place of love, so it doesn’t anger him. Tony sighs.

“It doesn’t mean you should trust the first person you meet outside this pod. Especially not if he’s a species that _eats_ our kind.”

“He doesn’t,” Bucky refutes, calm and gentle. “He doesn’t eat humans or merpeople.”

“And you know that how?” 

“He told me.”

Tony shakes his head. “Because nobody ever lies to get something they want.”

Bucky shrugs away. Steve isn’t lying, but he doesn’t know how to make Tony understand. He’s not sure he understands his own feelings, to be honest.

“Are you kicking me out of the pod?”

“What?” Tony exclaims. “No!”

“Okay. Then I’m going to go see Steve now.”

“ _Steve_ ,” he hears Tony say as he swims away, in affronted disbelief.

  
  
  


“They don’t like me hanging around you,” Bucky says, after an hour or two of silence. Steve is sunning on his rock, and Bucky is lounging in the tidepool just beneath him. He notes with some pride that Steve’s filling out a little bit; there are a lot of lionfish in the sea. It’s been a good season for whelks, too.

“I wouldn’t, either.”

That response surprises Bucky. Angers him a little, too.

“Why not? You’re kind and funny and principled.”

“Eh,” Steve says, “I’m mostly just dead weight. I know that.”

For the first time in a very long time, Bucky loses his temper. He flops up on the shore with a flex of his tail and pulls himself up next to Steve, planting a finger in the middle of his chest. “I don’t know who told you that, but they were cruel and they were wrong. So don’t let me catch you repeating it,” he growls.

“I’m just stating the facts,” Steve insists, mulish. “Ain’t gotta do me any favors. Your pod is right. There’s better people you could waste time with.”

“Is that what this is to you?” he asks, more hurt than he should be. “A waste of time?”

Steve’s eyes go wide. “No! No, that’s not what I meant, I meant _I’m_ a waste of time, I don’t have anything to offer you.”

“How about you let _me_ decide what I get out of this?” Bucky demands. If there’s anything he can’t stand after his captivity, it’s people trying to tell him how he feels, or make decisions for him. He was powerless for long enough. He’ll never allow that again. If this moron thinks he can rationalize himself out of Bucky’s life, he’s got another thing coming.

Steve holds up his hands, placating. “Okay, okay. I’m sorry, Bucky.”

Ah. He must be making that face Clint told him about. The murdery one.

“You have to tell me your secret,” another voice says, and they both look toward it, startled. It’s another siren. He’s dark-skinned and very handsome. “Because I have never _once_ been able to get through to this fool, let alone get him to apologize for something.”

“Well, you’re not a pretty merman,” Steve fires back, gone from contrite to full sass in the space of a second. The other siren laughs a full-belly laugh and Bucky likes him instantly.

That’s how he meets Sam, Steve’s other kin.

  
  
  


He will not indulge the fluttery, childish thought of: _he thinks I’m pretty_. No, he absolutely will not. Steve was just picking on Sam. That’s all it was.

  
  
  


He asks Pepper to come with him the next time he visits Steve. It’s only fair that Steve meets some of his kin, and Pepper’s vote of confidence will go a long way in soothing Tony and the rest of the pod. She agrees right away.

If she’s nervous, she doesn’t show it. She has nerves of steel. Pepper is the rare creature who believes in the goodness of others, but is always prepared in case people fall short.

Steve doesn’t. He _couldn’t_ , Bucky knows that, but he and Pepper hit it off right away. She loves his strong stance on what he will and won’t eat and they eagerly lose themselves in a conversation about invasive species and the impact humans have on waters around the world. It’s the most he’s ever heard Steve talk at once.

He’s tired afterward, and they lay together in the shallows listening to the tide.

  
  
  


Bucky does the talking next time, after a meal of green crabs. He tells Steve what he can bear to repeat about his captivity and escape. It’s still painful to think about, but he won’t spiral. It’s been a long time since that happened.

Steve doesn’t offer platitudes. He just pulls Bucky against him and holds on.

Wow. That’s…

On so many levels, it’s exactly what he needed.

  
  
  


He thinks Natasha swims by at some point in the night, but she leaves them be.

  
  
  


“I...I think I want to mate with him.”

Natasha looks up from where she’s harvesting oysters. The meat is for him; she’s looking for a pearl to replace what she lost from one of her nipple piercings. “You’re talking about Bucky?”

He nods.

“Are you asking permission?”

“No,” Steve huffs. He doesn’t need anybody’s permission. It’s just...he’s never mated with anyone other than Natasha before, and although he knows his people aren’t generally monogamous, he doesn’t want to hurt her feelings.

“Mmm.” She keeps rummaging. No pearls yet.

“ _Well?_ ” he demands after an interminable five minutes.

“Well, I don’t know how, but I’m sure you’ll make it work,” she says, like it’s the simplest thing in the world.

  
  
  


For some reason, Steve is fidgety as all hell today. He can’t seem to sit still.

“If this is a bad time,” Bucky starts, “I can come back tomorrow.”

“No.” Steve descends from his rock and slides into the tidepool, sitting with his chin on his knees. “Do you have a mate, Bucky?”

He shakes his head. It’s not for lack of interest on his part or anyone else’s. He just hasn’t felt ready.

“Do you?”

“Not...currently,” Steve says, and he sounds a little too careful.

“What does that mean?”

Steve sighs, wiggling his toes and making little ripples in the water. “It’s normal to mate with your kin.”

“Oh.” Bucky tries to understand what he isn’t saying. “So you and Natasha and Sam…”

“Not Sam. Sam has other kin somewhere. His name is Riley.” He smiles faintly. “You see, my mother and father once fought him for this spot and they won. I think Sam is afraid we wouldn’t get along because of that. I keep telling him it’s fine. Maybe he’ll listen one day.”

“You say a lot of things are fine when they aren’t,” Bucky points out. “And maybe it’s Riley who isn’t fine with it.”

Steve tilts his head, conceding the point.

“You and Natasha, though?” Bucky asks. As much as Natasha frightens him, he can see that she’s loyal to Steve, and she obviously has good taste. Pretty merman or not, he can’t really compare to her.

“Sometimes.”

“Is something going on between you?” He can be sympathetic. That’s what friends do; they offer support when hearts are hurting. Even if one of those hearts is, inexplicably, his.

“No, everything’s fine. Sirens aren’t monogamous. She’s free to mate with whoever she wants.” Steve turns his head, and for the first time, he looks tentative. “So am I.”

It takes Bucky almost a full minute to understand.

“Oh,” he says, going warm down to his tailfin. Just like that, he’s the one gone fidgety. He doesn’t quite know what to do with himself. “I, uh…”

“It’s okay if the answer is no. It’s not exactly conventional,” Steve chuckles. There’s worry beneath the humor, though.

He doesn’t need to worry. Bucky has been trying to deny his own attraction because he thought it was one-sided. Once upon a time he might have been brave enough to hope, or even come right out and ask, but since his escape he’s mostly been interested in sparing himself pain where he can. 

There are few guarantees in life, but he knows that Steve would never, ever hurt him. He’s not talking about a casual fling. He’s talking about becoming kin. Bucky knows what that means to him. 

It’s an easy yes. Bucky swallows, meets his eyes, and gives a shy nod. The worry lifts off Steve like birds rising into the sky. Something nags at Bucky, though, because he wants...he wants to be worth it, for him.

“How do we even…”

“Well, Bucky...” Steve’s lips twitch, and then he grins in a way that makes Bucky’s anxiety evaporate. “When two sea creatures love each other very much…”

“Shut up,” Bucky laughs, and tackles him. 

  
  
  


It should be awkward, but they both want it so much that it’s full speed ahead, armed with determination and good humor. They touch with eager reverence, exploring one another’s bodies. Everything is external on Steve; not like Bucky’s body, where his tender parts stay within a cavity in his tail until he’s ready to mate. Steve is ready very fast, thick and smooth as silk in Bucky’s hand. He likes the way Steve rolls his hips and pushes into the circle of his fist, chasing the sensation without shame. 

It’s a bit slower for Bucky. Steve gamely strokes his fingers where Bucky shows him, mimicking his movement and pressure, coaxing the membranes to relax. He’s forgotten what it’s like to be touched with such care. The tip of his cock starts to fill and press forward, to the dull, sweet pressure of Steve’s palm. 

He meets Steve halfway when he leans forward to kiss him. Kissing is the same, although Steve likes to bite. Those teeth are _sharp_. The pinprick pain makes Bucky jump, but combined with the play of Steve’s fingers, it also makes him more aroused than he can remember being in a long, long time.

Steve pulls back, brows raised. Bucky knows he’s probably showing now. Not all the way, yet, but it’s a damn good start. 

“That - that’s good?” Steve asks, taking him in.

Bucky nods enthusiastically.

“Can I touch?”

“Yes,” he breathes. “And keep kissing me.”

Steve obliges. His hands are careful. His teeth less so. Bucky moans as those tiny daggers tease the cords of his neck. It’s not even hard enough to break the skin, but the scrape lights him up. He swells and elongates in Steve’s palm. Steve strokes his cock lightly, distracted with examining it for a moment. No doubt he’ll notice that Bucky’s longer, not as thick, but much more rigid. He’s not smooth like Steve, either. His kind are textured, designed for stimulation. Steve isn’t put off in the least. He traces some of the ridges and nubs with a gentle fingertip and then follows with his tongue. Bucky’s eyes roll back. That feels unspeakably good. 

He’s fully erect now, everything out on display. Even his testicles have eased free from the protection of his body. That doesn’t always happen. Steve’s eyes are dark and hungry as they travel over him.

“I meant it when I said you were pretty,” he says. “Didn’t know how right I was.”

“You, too,” Bucky breathes, stroking fingers through his hair. “You’re so beautiful.”

Steve makes a soft scoffing noise. “You don’t have to flatter me, Bucky. I’m a sure thing.”

Bucky tugs his hair, and not terribly gently. It _irks_ him that Steve doesn’t seem to know how amazing he is. “It’s the truth,” he asserts, with murder face in full effect, “and I’m going to fuck you ‘til you believe it.” He can’t help the way his voice gets hot and hard with promise.

Steve shivers, his cock twitching. “Mmm.” He’s heavy-eyed with arousal now, self-deprecation forgotten. “You can start any time.”

And Steve’s slender body really doesn’t look like it should be able to accommodate all that Bucky has to offer - it’s substantial - but when Bucky lines them up, he sinks all the way down over his cock like a champion. He just _goes after it_. He’s rock-hard and flushed up to his hairline as he starts to ride him. 

Bucky can’t look away. He’s never seen it from this angle before because - well, because merfolk don’t have _legs_ . There aren’t many positions that work for penetration. He’s never been able to _watch_ his cock slide into his partner like this. Holy fuck, the _feeling_ is incredible enough, but this? Slack-jawed, Bucky lets him go until his breathing gets too rough.

Then he remembers he’s supposed to be taking care of Steve, too, and bucks them to the side with a flick of his tail. Steve starts to protest but Bucky muffles it with his mouth. Steve gives him his clever little tongue, but also an impertinent nip. Bucky tastes blood.

He likes to think that he’s always been a gentle and considerate lover. Right now, Steve clearly doesn’t want any of that, and it’s really, really doing it for Bucky. He turns them further so Steve’s on his back and pins his hips down with his hands. Steve stares up at him, breathing hard, tongue tasting Bucky’s blood on his lips. He is the most gorgeous thing Bucky has ever seen.

He makes a little _eep_ sound when Bucky unceremoniously drags him further out. He needs to be a little deeper in the water for this. Once he is, he can use the strong and tireless muscles of his tail to fuck Steve senseless. That’s exactly what he does, holding him in place, pounding him until he starts to arch out of the water, scales flashing blue and red in the sunlight. Steve lets out a noise that’s not quite song, but not anything else Bucky can describe, either. It digs beneath Bucky’s skin with a clawing, primal urgency. Before he knows what he’s doing, he puts his own teeth to Steve’s chest and bites down hard in a way he’d never dare with one of his own. Trembles and gasps turn into a hard, convulsive thrash as Steve starts to climax beneath him.

“Bucky!” seems to be the only word he remembers for the next minute. “ _Bucky,_ ah! _”_

Oh, that’s wonderful. 

Bucky slows and Steve quiets, though his heartbeat vibrates in Bucky’s ribcage. He likes that a lot. He likes the pulse of him around his still-hard cock even more. “You okay?” he asks, breathless.

“Very okay.”

“This might be a good time to tell you that merfolk can go for hours,” he says into the sensitive skin over his gills.

Steve sits up on his elbows, eyes bright and besotted. “ _Hours_?”

“Uh huh.” Bucky rubs gently at the spot on his hip that now bears a red imprint of his fingers. “You wanna turn over?”

“Yup,” Steve says, without even a trace of hesitation, and slithers around.

  
  
  


He makes his way home, unaware that he looks like he was in a fight.

“What the hell happened to you?” Maria asks, alarmed.

“Steve,” Bucky says, with a dopey smile.

Pepper laughs and Tony facepalms and Bucky drifts off to eat his weight in that day’s bounty.

  
  
  


Steve is aware that he’s unusually docile the next day. Sam brings him a fish and he accepts it without a fight, and then falls asleep on Sam’s shoulder for a little while. He’s tired, but pleasantly so - the fatigue of a job well done. His mind is calm and blessedly empty.

Maybe not entirely empty. He’s thinking about what happens inside Bucky’s body once he’s erect. Is there still space? Could he put his fingers in there, or his cock? Would it feel good for Bucky? Would it feel good for _him_? He doesn’t care about that as much as he cares about Bucky, but he’s going to find out. 

  
  
  


The answer is yes, there’s space in there, and though Bucky’s never done it before, he knows that others do. He’s more than willing to try. 

Steve doesn’t need to ask if it’s good. Bucky shoots the biggest load he’s ever seen all over both of them and is all but unresponsive when it’s done. And that was just from his cock; Steve is pretty sure he can fit his whole fist in there.

Maybe next week.

  
  
  


“Steve,” Bucky slurs. Steve’s hand is still inside him. Bucky is blood-hot within, which surprises him just like it did the first two times. He wouldn’t expect that from someone who’s part fish. 

He’s already decided he wants Bucky to return the favor tomorrow. He’s getting hard again just thinking about it. He loves driving Bucky out of his mind, but he also loves that Bucky gives as good as he gets.

“ _Steve_ ,” Bucky says, a trace of a whine in his voice now.

“Yeah, Buck,” he hums.

“I don’t want you to put your fist in anyone else.”

They’ve been avoiding talking about the exclusivity thing, but it seems like Bucky’s guard is down enough to finally say what Steve already knows. He smiles. As declarations of love and devotion go, that isn’t half bad. 

Steve licks at the spunk on his chest. It tastes like caviar. He’s a fucking delicacy, and he’s all Steve’s.

“Wouldn’t dream of it, sweetheart.”

  
  
  


It’s funny, what a difference a year makes.

One year ago today, Bucky poked his head above water for the first time in three years. That day, he saw someone who should have been like him; cautious, skittish, reliant on others. But Steve the tone-deaf siren was none of those things. He raged against his limitations and his detractors in a way Bucky had never seen.

It’s true that Steve is sometimes strong-willed to the point of stupidity, but Bucky needed to see that. He needed to be shown that he could just... _refuse_ to be defined by anyone or anything other than himself. It took him a while to be strong enough to find his identity outside his trauma, but there’s no way it would have happened without Steve. He’d still be hiding under the water or behind the fins of his pod.

Steve is in their nest, sleeping hard. He should be; Bucky spent most of the night making love to him slow, the way his own people like. Steve is rarely patient enough for that. Last night, though, he didn’t seem to be in any particular rush, and Bucky knew to take the chance when he got it.

As if he knows Bucky is thinking about him, Steve stirs. He turns to his side in the woven hammock and lets a hand trail down toward the water. Bucky reaches up from his spot in the tidepool to brush his fingertips.

“Hello, beautiful,” he says.

Steve doesn’t open his eyes, but he gives Bucky’s hand a little squeeze. “Mornin’.”

That’s it. No huff of breath, no eye roll, no protest at the praise. 

Bucky smiles so hard his face hurts.

What a difference, indeed.

  
  
  
  
  
  
  



End file.
